Semiconductor light emitting device and multiple lead frame for semiconductor light emitting device

ABSTRACT

A semiconductor light emitting device that is excellent in radiating heat and that can be molded into a sealing shape having intended optical characteristics by die molding is provided. The semiconductor light emitting device includes: a lead frame including a plate-like semiconductor light emitting element mounting portion having an LED chip mounted on a main surface, and a plate-like metal wire connecting portion extending over a same plane as the semiconductor light emitting element mounting portion; a metal wire electrically connecting the LED chip and the metal wire connecting portion; a thermosetting resin molded by die molding or dam-sheet molding so as to completely cover the LED chip and the metal wire; and a resin portion provided to surround the lead frame and having the thickness not greater than the thickness of the lead frame.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.13/799,063, filed Mar. 13, 2013, which is a divisional of U.S.application Ser. No. 12/046,896, filed Mar. 12, 2008 (U.S. Pat. No.8,415,681), which claims the benefit of Japanese Patent Application No.2007-063698 filed on Mar. 13, 2007, the entire contents of each of whichare hereby incorporated by reference.

BACKGROUND

1. Field of the Technology

The technology presented herein relates to a semiconductor lightemitting device on which a semiconductor light emitting element ismounted, and a multiple lead frame for a semiconductor light emittingdevice.

2. Description of the Background Art

Conventional semiconductor light emitting devices are disclosed in, forexample, Japanese Patent Laying-Open Nos. 2004-274027, 07-235696 and2002-141558. As shown in FIG. 21, a conventional semiconductor lightemitting device includes a lead frame 101 having a main surface 101 a,an LED (Light Emitting Diode) chip 104 provided on main surface 101 a, ametal wire 105 connecting lead frame 101 and LED chip 104, epoxy resin106 provided on main surface 101 a so as to completely cover LED chip104 and metal wire 105, and a resin portion 103 provided so as tosurround epoxy resin 106.

Resin portion 103 is provided around lead frame 101 by insert molding,for example. Resin portion 103 forms a concave shape on main surface 101a. LED chip 104 is mounted on main surface 101 a, with a silver (Ag)paste 107 interposed, to be located inside the concave shape. Anelectrode formed on the top surface of LED chip 104 is connected to mainsurface 101 a of lead frame 101 via metal wire 105. Epoxy resin 106 isprovided on main surface 101 a so that LED chip 104 and metal wire 105are covered and the concave shape is completely filled therewith.

A manufacturing method of the semiconductor light emitting device shownin FIG. 21 is now described. Firstly, plate-like lead frame 101 isprocessed into a prescribed pattern. Lead frame 101, plated with silver(Ag), is insert-molded in resin portion 103. Thereafter, LED chip 104 ismounted on main surface 101 a with silver paste 107 being interposed.LED chip 104 and main surface 101 a are electrically connected via metalwire 105. Thereafter, LED chip 104 and metal wire 105 are sealed withepoxy resin 106. Lastly, a lead terminal projecting into the peripheryand extending in a prescribed direction is cut so as to be cut away fromunnecessary portions of lead frame 101.

Resin portion 103 shown in FIG. 21 plays the role of controllingdirectivity of light by reflecting the light emitted from LED chip 104with the concave-shaped sidewall, and also the role of keeping the shapeof lead frame 101 having formed in a prescribed pattern. In the step ofresin-sealing LED chip 104 and metal wire 105, liquid epoxy resin 106 isdropped into the concave shape formed by resin portion 103 andthereafter cured. However, according to this method, the shape of epoxyresin 106 is limited to the shape of the concave shape formed by resinportion 103, and the optical characteristics by the shape of resinsealing cannot be controlled. Further, dropped epoxy resin 106 tends tobe affected by its viscosity, and therefore the filling amount may bevaried. Additionally, there are the effect of vaporization of volatilecomponent or cure shrinkage during thermal curing. Therefore, it isdifficult to ensure uniform sealing shape.

When epoxy resin 106 and resin portion 103 are adhered to each other asin the conventional technique, since adhesion force between epoxy resin106 and resin portion 103 is weak, they may possibly be peeled off fromeach other after molding and the optical characteristics may beimpaired. In fact, it has been observed in a long-term aging test thatan optical characteristics defect occurs due to peeling between epoxyresin 106 and resin portion 103.

For stabilizing the sealing shape of epoxy resin 106 and for moldinginto various sealing shapes, molding using a die (die molding) may beemployed. In order to perform die molding, it is necessary for the frontand rear surfaces of lead frame 101 to be flat. However, as resinportion 103 is protruding on main surface 101 a of lead frame 101,clamping of the die is difficult. Japanese Patent Laying-Open No.2004-274027 also discloses die molding in a state where resin portion103 protrudes on main surface 101 a of lead frame 101 (see paragraph0059 of the specification of Japanese Patent Laying-Open No.2004-274027). However, sealing only the periphery of LED chip 104 withepoxy resin 106 is difficult because of the limited clamping region andin consideration of keeping the region for resin gate and runner.

A metal core substrate, a ceramic substrate or the like that can beformed to have a flat surface may be employed for performing diemolding. However, while the ceramic substrate is higher in thermalconductivity than a conventional resin substrate such as a glass epoxysubstrate (for example, about 20 W/m·K in the case of alumina), the unitprice of the substrate is increased. Also, there is a disadvantage thatit is easily damaged when clamped by the die. On the other hand, themetal core substrate requires an insulating layer to be provided betweenthe substrate pattern and the metal being the core. This insulatinglayer reduces the thermal conductivity. That is, there has been no leadframe provided that have the thermal conductivity of the same level asthat of a metal frame and that can be die-molded.

SUMMARY

A primary feature of an example embodiment presented herein is toprovide a semiconductor light emitting device and a multiple lead framefor a semiconductor light emitting device, which are excellent in heatradiation and which is easily applied to die molding for ensuring thesealing shape having intended optical characteristics.

A semiconductor light emitting device according to the presentembodiment includes: a lead frame including a plate-like semiconductorlight emitting element mounting portion having a semiconductor lightemitting element mounted on a main surface, and a plate-like metal wireconnecting portion extending over a same plane as the semiconductorlight emitting element mounting portion; a metal wire electricallyconnecting the semiconductor light emitting element and the metal wireconnecting portion; a sealing resin molded by die molding or dam-sheetmolding so as to completely cover the semiconductor light emittingelement and the metal wire; and an insulator provided so as to surroundthe lead frame and having thickness not greater than thickness of thelead frame.

The semiconductor light emitting device configured as above have thestructure in which the semiconductor light emitting element is mountedon the main surface of the lead frame made by metal having great thermalconductivity, and there is no material of great thermal resistance suchas an insulating substrate interposed in a heat radiation route forradiating heat generated by the semiconductor light emitting element tothe outside. Accordingly, the semiconductor light emitting device thatis excellent in radiating heat can be formed. Additionally, as thethickness of the insulator is not greater than the thickness of the leadframe, a flat surface having no projection on the main surface of thesemiconductor light emitting device can be formed.

Accordingly, as a method of sealing the semiconductor light emittingelement, die molding using liquid or solid resin can easily beincorporated, in addition to a conventional potting method where liquidresin is dropped. When potting is employed, dam-sheet molding can beincorporated. This allows the sealing resin to be molded into a sealingshape based on the optical characteristics required for the product,such as a cylindrical shape, a dome shape or the like.

Furthermore, since resin is allowed to cure inside the die or the damsheet, the conventional problems in liquid resin sealing can besuppressed, such as variations in the dropping amount attributed to achange in viscosity and variations in the sealing shape attributed tovaporization of volatile component during curing or cure shrinkage.

Desirably, the insulator is thermoplastic resin or thermosetting resin.Then, the insulator can easily be molded.

Desirably, a concave portion is formed at least at the semiconductorlight emitting element mounting portion on the main surface of the leadframe, and the semiconductor light emitting element is mounted on abottom surface of the concave portion. Then, by providing thesemiconductor light emitting element on the bottom surface of theconcave portion, a product having the optical characteristics thatcannot be controlled solely by the shape of the sealing resin, inparticular, having higher directivity characteristics than asemiconductor light emitting device without concave portion, can beobtained.

Desirably, the lead frame has a wedge structure for preventing theinsulator from peeling. Then, by pouring the insulator into the wedgestructure when molding the insulator, peeling or removal of theinsulator from the lead frame can be prevented.

Desirably, the semiconductor light emitting device further includes alead terminal projecting from periphery of the insulator into a sideaway from the semiconductor light emitting element. While cuttingprocessing is performed for singulating the semiconductor light emittingdevice in the manufacturing process of the semiconductor light emittingdevice, with the semiconductor light emitting device configured asabove, cutting by the die can be performed, in addition to theconventional dicing method. Oxidation of the cutting surface of metaldisadvantageously reduces wettability to solder (that is, in soldering,the solder alloy having the function of bonding and the portion to bebonded becomes less conformable to each other, and the solder becomesgranular on the surface to be bonded). In the semiconductor lightemitting device of the present invention, as the lead terminal projectsfrom the insulator, margin for solder can be ensured not only at thecutting surface but also at the side surface of the lead terminal. Thus,reduction in solder wettability can be avoided.

Desirably, the semiconductor light emitting device further includes areflector provided on the main surface so as not to contact the sealingresin, or a reflector provided on a side away from the semiconductorlight emitting element relative to periphery of the insulator. With thesemiconductor light emitting device configured as above, the opticalcharacteristics that cannot be controlled solely by the shape of thesealing resin sealing the semiconductor light emitting element can beobtained. At the same time, it becomes possible to extract the lightgenerated by the semiconductor light emitting element to the outsidemore efficiently.

A multiple lead frame for a semiconductor light emitting deviceaccording to the present invention includes a lead frame base memberformed by a plurality of the lead frames constituting the semiconductorlight emitting device. The multiple lead frame for the semiconductorlight emitting device further includes an insulator base member, withwhich all gaps formed in the lead frame base member so as to surroundthe lead frame are filled, and which is to be the insulator constitutingthe semiconductor light emitting device. The multiple lead frame for thesemiconductor light emitting device is formed into a substrate-likeform.

Then, by cutting the multiple lead frame for the semiconductor lightemitting device along the outer shape of the semiconductor lightemitting devices linearly arranged, the semiconductor light emittingdevices can be singulated. That is, by cutting and separating themultiple lead frame for the semiconductor light emitting device formedby a plurality of lead frames and insulators constituting thesemiconductor light emitting devices by a rotary blade, laser or thelike, a plurality of semiconductor light emitting devices each havingsingle lead frame and single insulator surrounding the lead frame can beobtained.

Another multiple lead frame for a semiconductor light emitting deviceaccording to the present invention includes a lead frame base memberformed by a plurality of the lead frames constituting the semiconductorlight emitting device. The multiple lead frame for the semiconductorlight emitting device further includes an insulator base member, withwhich gaps formed in the lead frame base member so as to surround thelead frame are filled, and which is to be the insulator constituting thesemiconductor light emitting device. The multiple lead frame for thesemiconductor light emitting device is formed into a substrate-likeform. A groove structure not being filled with the insulator base memberis formed in part of the gaps.

Then, when cutting the multiple lead frame for the semiconductor lightemitting device, cutting can be performed by a cutting die. Cutting themetal portion of the multiple lead frame for the semiconductor lightemitting device by the cutting die and cutting the resin portion as aninsulator by dicing, the cutting defect such as burr generated when themetal and resin are cut at the same time by dicing can be prevented.Furthermore, as the characteristics test of the semiconductor lightemitting device can be performed not only for each singulatedsemiconductor light emitting device but also for each multiple leadframe, the production efficiency can be improved.

Desirably, the insulator base member is formed by a plurality ofindividual insulators. Then, a plurality of insulators can be molded atthe same time. When the insulator is resin, the insulator base membercan easily be cut and separated by dicing.

Desirably, the lead frame base member has a key structure for preventingthe insulator base member from being disconnected. Then, the joiningforce between the lead frame base member and the insulator base membercan be improved, and therefore the insulator base member is preventedfrom being separated and disconnected from the lead frame even when thelead frame base member is cut by the die.

Still another multiple lead frame for a semiconductor light emittingdevice according to the present invention includes a lead frame basemember formed by a plurality of the lead frames constituting thesemiconductor light emitting device. The multiple lead frame for thesemiconductor light emitting device further includes an insulator basemember, with which gaps formed in the lead frame base member so as tosurround the lead frame are filled, and which is to be the insulatorconstituting the semiconductor light emitting device. The multiple leadframe for the semiconductor light emitting device is formed into asubstrate-like form. The lead frame base member has a skeleton frame,and the insulator base member is divided by the skeleton frame for eachinsulator surrounding the lead frame.

Then, by cutting the multiple lead frame for the semiconductor lightemitting device by a cutting die, the semiconductor light emittingdevice can be singulated. Therefore, it is not necessary to cut bydicing and the production efficiency can further be improved.

The semiconductor light emitting device is excellent in heat radiationand can be easily applied to die molding for ensuring the sealing shapehaving intended optical characteristics.

The foregoing and other features, aspects and advantages of the presentembodiment will become more apparent from the following detaileddescription of the present embodiment when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a cross section of a semiconductorlight emitting device of a first embodiment.

FIG. 2 is a plan view of the semiconductor light emitting device shownin FIG. 1.

FIG. 3 is a flowchart showing a manufacturing method of thesemiconductor light emitting device of the first embodiment.

FIG. 4 is a schematic diagram of a multiple lead frame of the firstembodiment.

FIG. 5A is a plan view of a portion forming a lead frame in thesemiconductor light emitting device, in a shape before surrounded by aninsulator.

FIG. 5B is a cross-sectional view along line VB-VB shown in FIG. 5A.

FIG. 5C is a cross-sectional view along line VC-VC shown in FIG. 5A.

FIG. 5D is a cross-sectional view along line VD-VD shown in FIG. 5A.

FIG. 6 is a schematic diagram showing a cross section of a semiconductorlight emitting device of a second embodiment.

FIG. 7 is a schematic diagram showing a cross section of a semiconductorlight emitting device of a third embodiment.

FIG. 8 is a plan view of the semiconductor light emitting device of thethird embodiment shown in FIG. 7.

FIG. 9 is a schematic diagram showing a cross section of a semiconductorlight emitting device of a fourth embodiment.

FIG. 10 is a plan view of the semiconductor light emitting device of thefourth embodiment shown in FIG. 9.

FIG. 11 is a flowchart showing a manufacturing method of thesemiconductor light emitting device of the fourth embodiment.

FIG. 12 is a schematic diagram of a multiple lead frame of the fourthembodiment.

FIG. 13 is a schematic diagram showing a state where a punched portionis formed in the multiple lead frame.

FIG. 14 is a flowchart showing a manufacturing method of a semiconductorlight emitting device of the fifth embodiment.

FIG. 15 is a schematic diagram of a multiple lead frame of the fifthembodiment.

FIG. 16 is a schematic diagram showing a cross section of asemiconductor light emitting device of a sixth embodiment.

FIG. 17 is a perspective view showing a package of collective reflector.

FIG. 18 is a perspective view showing a state where the package ofreflector is placed on a mounting substrate.

FIG. 19 is a schematic diagram showing a cross section of asemiconductor light emitting device of a seventh embodiment.

FIG. 20 is a flowchart showing a manufacturing method of thesemiconductor light emitting device of the seventh embodiment.

FIG. 21 is a schematic diagram showing a representative cross section ofa conventional semiconductor light emitting device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, based on the drawings, embodiments will be described.In the following description, the same or corresponding parts aredenoted by the same reference numbers, and description thereof will notbe repeated.

First Embodiment

As shown in FIGS. 1 and 2, a semiconductor light emitting deviceincludes a lead frame 1 having a main surface 1 a, a resin portion 2 asan insulator provided so as to surround lead frame 1 and to have thethickness not greater than that of lead frame 1, an LED chip 4 as asemiconductor light emitting element provided on main surface 1 a, ametal wire 5, and a thermosetting resin 3 as a sealing resin provided soas to completely cover LED chip 4 and metal wire 5.

Lead frame 1 includes a semiconductor light emitting element mountingportion 1 c having LED chip 4 mounted on main surface 1 a. Lead frame 1also includes a metal wire connecting portion 1 d that is electricallyconnected to LED chip 4 by metal wire 5 and that extends over the sameplane as semiconductor light emitting element mounting portion 1 c.Semiconductor light emitting element mounting portion 1 c and metal wireconnecting portion 1 d are surrounded by resin portion 2. Resin portion2 forms the outer shape of the semiconductor light emitting device.

Semiconductor light emitting element mounting portion 1 c and metal wireconnecting portion 1 d have plate-like shape, and are separated fromeach other by prescribed patterning. Between the separated semiconductorlight emitting element mounting portion 1 c and metal wire connectingportion 1 d, a slit-like groove 1 m is formed, which extends from mainsurface 1 a to a rear surface 1 b opposite to main surface 1 a.Semiconductor light emitting element mounting portion 1 c and metal wireconnecting portion 1 d are electrically insulated from each other byslit-like groove 1 m which is filled with a resin material that is thesame insulator as resin portion 2. That is, as will be described later,when resin portion 2 is filled with a resin material, slit-like groove 1m is filled with the same resin material with which resin portion 2 isfilled.

LED chip 4 is provided on main surface 1 a of semiconductor lightemitting element mounting portion 1 c. LED chip 4 is fixedly held onmain surface 1 a of semiconductor light emitting element mountingportion 1 c with a conductive paste such as a silver (Ag) paste 6interposed. An electrode provided on a top surface 4 a of LED chip 4(that is, the surface that is opposite to the surface facing lead frame1 and that is on the upper side in FIG. 1) is connected by metal wire 5made of, for example, gold (Au), to metal wire connecting portion 1 dthat is separated from semiconductor light emitting element mountingportion 1 c by slit-like groove 1 m. That is, LED chip 4 is electricallyconnected to main surface 1 a by silver paste 6 and metal wire 5.

One end 5 p of metal wire 5 connected to the electrode of LED chip 4 isformed in a ball-like shape. The other end 5 q of metal wire 5 connectedto metal wire connecting portion 1 d is formed in a linear shape. Thus,metal wire connecting portion 1 d and the other end 5 q can be bonded byball-bonding, and LED chip 4 and one end 5 p can be bonded by wedgebonding. One end 5 p of metal wire 5 is connected to LED chip 4 in alow-loop manner. This allows metal wire 5 to be provided more nearly tomain surface 1 a of lead frame 1, and therefore the amount ofthermosetting resin 3 required to completely cover LED chip 4 and metalline 5 can be reduced.

When current is passed through LED chip 4, heat is generated togetherwith light. The heat is conducted to semiconductor light emittingelement mounting portion 1 c, and therefrom radiated outside thesemiconductor light emitting device such as a mounting substrate. In thepresent embodiment, by providing semiconductor light emitting elementmounting portion 1 c with a sufficient thickness, the heat generated inLED chip 4 can efficiently be diffused.

When plate-like lead frame 1 is thicker, the heat accumulation thereofis improved and the heat generated in LED chip 4 is diffusedefficiently. However, due to limitations in processing, slit-like groove1 m becomes wider as lead frame 1 is thicker. That is, in order to avoidmisalignment in assembling lead frame 1, high processing accuracy isrequired for lead frame 1. However, because it is difficult to requirethe processing accuracy of the size not greater than the thickness of aplate material in die mold processing, it is necessary to increase thewidth of slit-like groove 1 m when lead frame 1 is designed to be thick.Accordingly, in order to reduce the semiconductor light emitting devicein size, the thickness of the lead frame is to be about 1.5 mm, at amaximum.

In order to attain efficient heat radiation from lead frame 1, leadframe 1 is formed by a metal having heat conductivity of not smallerthan 300 W/m·K. If the heat conductivity of the metal forming lead frame1 is smaller than 300 W/m·K, the effect of lead frame 1 diffusing andradiating heat generated by LED chip 4 will be insufficient.Specifically, oxygen-free copper is most desirable for its high heatradiation performance (heat conductivity: 391 W/m·K). On the other hand,for a certain structure and strength of lead frame 1, lead frame 1 canbe formed with sufficient frame strength by employing a copper (Cu)alloy containing metal such as iron (Fe), zinc (Zn), nickel (Ni),chromium (Cr), lead (Pb), or silver (Ag), although the heat conductivitywill be reduced. In the case where alloy is used, the heat conductivityof lead frame 1 can be increased with smaller amount of the metal addedto copper (Cu).

FIG. 1 shows the semiconductor light emitting device having only one LEDchip 4 mounted on lead frame 1. However, by patterning lead frame 1, aplurality of LED chips 4 may be mounted on a single semiconductor lightemitting device. With the semiconductor light emitting device having aplurality of LED chip 4 mounted, a high-output light source can beobtained. Also, for example, if an LED chip is mounted for each of blue,green and red base colors, it is possible to obtain a light source ofwhich color, such as white color, can be adjusted by adjusting currentdistribution to each of the LED chips.

When mounting a plurality of LED chips 4 on a single semiconductor lightemitting device, it is necessary to reduce the width of slit-like groove1 m formed between semiconductor light emitting element mounting portion1 c and metal wire connecting portion 1 d, to thereby reduce thesemiconductor light emitting device in size. Because of limitations inprocessing, thicker lead frame 1 results in wider slit-like groove 1 m.Accordingly, by reducing the thickness (for example, about 0.15 mm) ofthe lead frame 1 and narrowing groove 1 m, the semiconductor lightemitting device that is small and on which a plurality of LED chips 4can be mounted can be formed.

Resin portion 2 is molded so as to surround lead frame 1 (semiconductorlight emitting element mounting portion 1 c and metal wire connectingportion 1 d). Resin portion 2 is molded so as not to protrude on mainsurface 1 a and rear surface 1 b of lead frame 1, and so as to have thethickness not greater than that of lead frame 1. For allowing resinportion 2 to have increased surface area contacting lead frame 1 and toattain wedge effect, appropriate locations of main surface 1 a and rearsurface 1 b of lead frame 1 are processed, into which resin is insertedto form resin portion 2. Thus, peeling or disconnection of resin portion2 can be prevented, and the strength of the product can be improved. Theproduct strength can also be improved by using lead frame 1 of a contourstrip (that is, lead frame 1 having uneven thickness) produced by diemolding of a copper or copper alloy strip of varying thickness, andmolding resin portion 2 so as to surround the entire lead frame 1. Onrear surface 1 b of lead frame 1, a terminal portion for connecting thesemiconductor light emitting device to a mounting substrate or the likeis provided.

As the insulator with which resin portion 2 is filled, a materialexcellent in heat resistance is used, taking into account of a reflowstep in manufacturing. Desirably, it is formed by a white materialhaving a high reflectivity, to efficiently reflect the light generatedby LED chip 4. Further desirably, a material that is not degraded by thelight from LED chip 4 and that has a thermal expansion coefficient closeto that of lead frame 1 is used. As a specific material satisfying suchconditions, a thermoplastic resin such as liquid crystal polymer, apolyamide-based resin or the like may be used. A thermosetting resinsuch as epoxy resin may also be used as a material for forming resinportion 2. Ceramic such as alumina may also be used as a material forforming resin portion 2.

As shown in FIG. 1, thermosetting resin 3 as a sealing resin sealing LEDchip 4 and metal wire 5 is molded into a dome-like shape. It is moldedby die molding for ensuring its shape stability. When thermosettingresin 3 is molded by die molding, thermosetting resin 3 is uniformlymolded among the singulated semiconductor light emitting devices. As todie molding, injection molding (for example, transfer molding),compression molding or the like may be possible, and die molding havingthe best moldability can be selected. In the present embodiment, sealingis performed by transfer molding.

In conventional thermosetting resin 3 molded by transfer molding, marksof runners are left around the molded shape. In thermosetting resin 3molded by compression molding, marks of resin overflow are left aroundthe molded shape.

Here, a depression 1 e is formed at one surface, on main surface 1 aside, of the resin arranged inside slit-like groove 1 m. Depression 1 efunctions as a runner that is a flow channel for inserting athermosetting material in transfer molding, and as an air vent that is aroute for discharging air inside the die. Provision of depression 1 erealizes a structure in which the resin runner and the air ventnecessary for transfer molding are incorporated in the semiconductorlight emitting device. Therefore, it is not necessary to separatelyprovide the runner and the air vent when performing transfer molding.Accordingly, molding can be performed in such a manner that the marks ofrunners or air vents being cut are not left on thermosetting resin 3molded in a dome-like shape.

The size of depression 1 e for the resin runner for transfer molding canbe changed depending on its die-moldability, product strength andoptical design. That is, when particles such as fillers are contained inthermosetting resin 3 as a sealing resin, larger depression 1 e providesbetter moldability. On the other hand, excessively large depression 1 ereduces the volume of the resin with which slit-like groove 1 m isfilled and which connects semiconductor light emitting element mountingportion 1 c and metal wire connecting portion 1 d. Thus, the productstrength of the semiconductor light emitting device is reduced, and thelight emitted from LED chip 4 leaks outside. Accordingly, it isnecessary to determine the size of depression 1 e as appropriate, takinginto account of the product strength and optical characteristics of thesemiconductor light emitting device.

As a sealing resin sealing LED chip 4 and metal wire 5, thermosettingresin (for example, epoxy resin, silicone resin or the like) can beused. By the shape of thermosetting resin 3, the intended opticalcharacteristics can be provided to the light generated by LED chip 4. Byusing resin of high index of refraction as the sealing resin, forcertain optical characteristics required for the semiconductor lightemitting device, it is possible to dispense with a reflectorconventionally provided to the outer circumferential portion of aconventional semiconductor light emitting device.

Specifically, as shown in FIG. 1, by shaping the sealing resin in adome-like shape, the directivity angle of the light emitted from LEDchip 4 becomes small (that is, divergence of the light is suppressed).Conversely, for a product that does not require directivitycharacteristics, sealing can be performed with the sealing resin in acylindrical shape.

Further, the sealing resin plays the role of protecting LED chip 4 andmetal wire 5 from external physical or electrical contact.

Next, a manufacturing method of the semiconductor light emitting deviceshown in FIG. 1 is described. As shown in FIG. 3, first, in step (S1), ametal plate is patterned into a prescribed shape by appropriateprocessing means such as punch press processing, etching processing orthe like, and thereby a lead frame base member is prepared. Lead framebase member 201 shown in FIG. 4 is formed by a plurality of lead frames1 each constituting a semiconductor light emitting device. Lead framebase member 201 includes support frames 202 being the opposing edges oflead frame base member 201 and a plurality of skeleton frames 203bridging between support frames 202 to form a skeleton structure. Theportion forming semiconductor light emitting element mounting portion 1c and the portion forming metal wire connecting portion 1 d in thesemiconductor light emitting device shown in FIG. 1 are separated fromeach other in lead frame base member 201, and held as suspended byadjacent skeleton frames 203.

Here, taper processing or groove processing as a wedge structure forpreventing peeling of the insulator can be provided to lead frame basemember 201. FIGS. 5A to 5D show one of the regions enclosed by thealternate long and two short dashes line in FIG. 4, which is the portionforming lead frame 1 in the semiconductor light emitting device and inthe shape before surrounded by an insulator. As shown in FIGS. 5A to 5D,at appropriate portions of main surface 1 a and rear surface 1 b of leadframe 1, taper processing or groove processing is provided to form awedge structure 1 f. Thus, the contact area between lead frame 1 andresin portion 2 when being filled with resin portion 2 surrounding leadframe 1 is increased. That is, wedge structure if is the structure thatincreases the contact area between lead frame 1 and resin portion 2 asan insulator, by increasing the surface area of lead frame 1 byprocessing the surface of lead frame 1. Inserting resin into such wedgestructure if provides a wedge effect of preventing peeling ordisconnection of resin portion 2 from lead frame 1.

Next, in step (S2), a resin base member 207 to be resin portion 2 as aninsulator constituting the semiconductor light emitting device isformed. Resin base member 207 is formed by filling resin into all thegaps that are formed to surround the portion forming lead frame 1 inlead frame base member 201. Resin base member 207 can be formed byinsert molding, for example.

Here, a gap between the portion forming semiconductor light emittingelement mounting portion 1 c and the portion forming metal wireconnecting portion 1 d in the semiconductor light emitting device (thatis, the portion corresponding to slit-like groove 1 m in thesemiconductor light emitting device) is also filled with resin.Accordingly, in the semiconductor light emitting device shown in FIG. 1,resin portion 2 and slit-like groove 1 m are filled with the same resin.

Resin base member 207 is molded so as to have the thickness not greaterthan the thickness of lead frame base member 201. At the time pointwhere step (S2) is completed, lead frame base member 201 and resin basemember 207 are formed so as to be one substrate.

Next, in step (S3), a conductive paste such as thermosetting silverpaste 6 is applied to the surface of lead frame base member 201, whichsurface corresponds to main surface 1 a of the portion formingsemiconductor light emitting element mounting portion 1 c in thesemiconductor light emitting device. Then, die bonding is performed, inwhich LED chip 4 as a semiconductor light emitting element is mounted onmain surface 1 a with the conductive paste interposed.

Next, in step (S4), wire bonding is performed. In wire bonding,electrodes of the mounted LED chips 4 and the surface corresponding tomain surface 1 a of the portion forming metal wire connecting portion 1d in the semiconductor light emitting device are electrically connectedto each other by metal wire 5 that is produced by gold (Au) having adiameter of 20-30 μm, for example. Thus, an electric circuit is formedand the semiconductor light emitting device is rendered conductive.

In step (S5), sealing with resin is performed so that LED chip 4 andmetal wire 5 are completely covered, and the electric circuit isprotected as being shielded from the outside air. The resin used as thesealing member is thermosetting resin, and a transparent resin ofepoxy-based, silicone-based or the like can be used. When thesemiconductor light emitting device is a white illumination, a resincontaining phosphor such as Gd and Ce doped YAG(Yttrium-Aluminum-Garnet)-based phosphor can be used as the sealingresin.

Here, the sealing resin is molded by die molding using liquid or solidresin. Therefore, the sealing resin can easily be molded into a shapebased on the intended optical characteristics for the light generated byLED chip 4, such as dome-like shape shown in FIG. 1, and the shapestability of the sealing resin can be ensured. Since resin is allowed tocure inside the die, the conventional problems in liquid resin sealingcan be suppressed, such as variations in the dropping amount attributedto a change in viscosity or the like and variations in the sealing shapeattributed to vaporization of volatile component during curing or cureshrinkage.

Next, in step (S6), plating processing is provided to the rear surfaceof lead frame base member 201 (to the portion corresponding to rearsurface 1 b contacting the mounting substrate when the semiconductorlight emitting element is mounted on the mounting substrate, in thesemiconductor light emitting device shown in FIG. 1). Plating processingcan be performed using tin (Sn) and bismuth (Bi) plating, or tin (Sn)and lead (Pb) plating (solder plating), for example. At the time pointwhere step (S6) is completed, multiple lead frame 200 having a pluralityof semiconductor light emitting devices arranged in a matrix, as shownin FIG. 4, is completed.

Next, in step (S7), a dicing apparatus is used to cut multiple leadframe 200 along the outer shape of the semiconductor light emittingdevices arranged in a matrix (i.e., along the alternate long and twoshort dashes line in FIG. 4). Thus, the singulation is performed, wherethe plurality of semiconductor light emitting devices are cut frommultiple lead frame 200, each being separated into a singlesemiconductor light emitting device having single lead frame 1 and resinportion 2 surrounding lead frame 1. Thereafter, in step (S8), a step oftesting the semiconductor light emitting devices is performed.Thereafter, in step (S9), a taping step where the semiconductor lightemitting devices are prepared in a prescribed shipment condition isperformed.

As to the heat radiating performance of the semiconductor light emittingdevice described as above, the heat generated when LED chip 4 emitslight is firstly absorbed by semiconductor light emitting elementmounting portion 1 c having very high thermal conductivity, andthereafter radiated to the substrate and the like where thesemiconductor light emitting element is mounted. Since the heatgenerated by LED chip 4 as a semiconductor light emitting element canefficiently be radiated to the outside, the temperature of LED chip 4 isreduced and the temperature of the sealing resin covering LED chip 4 canalso be suppressed. Thus, even when LED chip 4 generates heat as a largecurrent is passed for ensuring high luminance of the semiconductor lightemitting device, reduction in light emitting efficiency or thermaldegradation, which occurs when phosphor being held as dispersed in thesealing resin is subjected to high temperature, can be prevented.Further, the life of the semiconductor light emitting device can beextended. Still further, variations in color of the light emitted fromLED chip 4 can be suppressed.

In molding the sealing resin, in the semiconductor light emitting deviceof the first embodiment, the thickness of resin portion 2 is not greaterthan the thickness of lead frame 1, and there are no protrusions on mainsurface 1 a and rear surface 1 b of lead frame 1. Therefore, the sealingresin can easily be molded by die molding, and the sealing shape canmore freely be modified for certain product characteristics. At the sametime, sealing with small variation in the shape of the sealing resin canbe attained. Further, for a certain semiconductor light emittingelement, by employing resin of high index of refraction, sufficientoptical characteristics can be obtained without using a reflector. As aresult, the product height of the semiconductor light emitting elementcan be reduced.

Further, by providing depression 1 e for the runner and air vent ofinjection molding in the resin arranged inside slit-like groove 1 m, therunner and the air vent can be incorporated in the semiconductor lightemitting device. When the shape of the sealing resin is reduced in size,it is difficult to surely provide the resin runner and the air vent, andthe moldability is affected. On the other hand, when the resin runnerand the air vent are increased in size, cutting marks of the runner orthe air vent will be left on the molded shape of the sealing resin. Byproviding the runner and air vent for sealing resin in the resinarranged inside slit-like groove 1 m, it becomes possible to perform diemolding which does not leave cutting marks of the runner and air vent onthe sealing resin.

Second Embodiment

As shown in FIG. 6, a semiconductor light emitting device of a secondembodiment is different from the semiconductor light emitting device ofthe first embodiment shown in FIG. 1 in the shape of thermosetting resin3 as a sealing resin and the shape of the resin arranged insideslit-like groove 1 m.

Specifically, thermosetting resin 3 is molded into a cylindrical shape.In the second embodiment, thermosetting resin 3 is molded by dam-sheetmolding. On the surface, on main surface 1 a side, of the resin arrangedinside slit-like groove 1 m, depression 1 e for runner and air vent ofinjection molding is not formed.

As used herein, the dam-sheet molding refers to a method of moldingthermosetting resin, wherein a sheet made of silicone, Teflon(registered trademark) or the like having a hole (a dam sheet) isattached to a lead frame, into which hole resin is poured by pottingmethod. In this state, the resin is thermally cured. Thereafter, the damsheet is peeled off to leave only the thermosetting resin on the leadframe.

As thermosetting resin 3 as a sealing resin sealing LED chip 4 and metalwire 5 is inserted by potting method into the hole formed in the damsheet, it is not necessary to provide depression 1 e for runner and airvent of injection molding. With the semiconductor light emitting deviceof the second embodiment configured as above, while the shape of thesealing resin is limited to the shape that can be molded by dam-sheetmolding, such as a cylindrical shape, a die for injection molding is notnecessary. With only the dam sheet, it can be manufactured with smallcapital investment. When filler or the like is contained in the sealingresin, the concentration of the filler in the sealing resin tends tovary if molding is performed by injection molding. On the other hand, bydam-sheet molding, variations in the filler concentration can besuppressed by dropping the sealing resin while agitating the resin in asyringe.

In thermosetting resin 3 molded by dam-sheet molding (potting molding),being different from the case of die molding, there are no marks ofresin runner or overflow, or marks of cut away runners or overflow resinaround the molded shape. In the semiconductor light emitting device inwhich thermosetting resin 3 is molded by dam-sheet molding, the moldedshape of thermosetting resin 3 is varied among the singulatedsemiconductor light emitting devices (that is, the amount of sealingresin is not constant).

The other configuration and manufacturing steps of the semiconductorlight emitting device of the second embodiment are the same as describedin the first embodiment, and therefore description thereof is notrepeated.

Third Embodiment

As shown in FIGS. 7 and 8, a semiconductor light emitting device of athird embodiment is different from the semiconductor light emittingdevice of the first embodiment shown in FIGS. 1 and 2 in the shape ofmain surface 1 a of lead frame 1.

Specifically, on main surface 1 a, concave portion 8 is formed oversemiconductor light emitting element mounting portion 1 c, slit-likegroove 1 m, and metal wire connecting portion 1 d. LED chip 4 as asemiconductor light emitting element is mounted on semiconductor lightemitting element mounting portion 1 c with silver paste 6 interposed, atbottom surface 8 a of concave portion 8. To bottom portion 8 a ofconcave portion 8 in metal wire connecting portion 1 d, metal wire 5extending from the top surface of LED chip 4 is connected. The side wallof concave portion 8 is formed to be tilted such that the opening areaof concave portion 8 on the same plane as main surface 1 a is greaterthan the area of bottom surface 8 a of concave portion 8.

In FIG. 7, depression 1 e for runner and air vent is formed on thesurface, on main surface 1 a side, of the resin arranged insideslit-like groove 1 m is formed for forming thermosetting resin 3 as asealing resin by injection molding. As described in the secondembodiment, depression 1 e is not necessary when sealing is performed bydam-sheet molding. With the semiconductor light emitting deviceconfigured as above, the same effect as described in the firstembodiment can be obtained. In addition, by providing LED chip 4 tobottom surface 8 a of concave portion 8, a product having the opticalcharacteristics that cannot be controlled solely by the shape of thesealing resin, in particular, having higher directivity characteristicsthan a semiconductor light emitting device without concave portion 8,can be obtained.

The other configuration and manufacturing steps of the semiconductorlight emitting device in the third embodiment are the same as describedin the first embodiment, and therefore description thereof is notrepeated.

Fourth Embodiment

As shown in FIGS. 9 and 10, a semiconductor light emitting device of afourth embodiment is different from the semiconductor light emittingdevice of the first embodiment shown in FIGS. 1 and 2 in that itincludes a lead terminal 7 projecting from the periphery of resinportion 2 as an insulator into a side away from LED chip 4 as asemiconductor light emitting element.

In FIG. 9, depression 1 e for runner and air vent is formed on thesurface, on main surface 1 a side, of the resin arranged insideslit-like groove 1 m is formed for forming thermosetting resin 3 as asealing resin by injection molding. As described in the secondembodiment, depression 1 e is not necessary when sealing is performed bydam-sheet molding.

In the fourth embodiment, resin portion 2 is formed so as to surroundlead frame 1 in a limited manner with a minimum resin amount thatensures the product strength of the semiconductor light emitting device.The end portion of lead terminal 7 for connecting to a mountingsubstrate or the like is not surrounded by resin portion 2. The diameterof lead terminal 7 is formed as small as possible in a range where theproduct strength of lead frame 1 is ensured, taking into considerationof cutting by a die in a manufacturing step of the semiconductor lightemitting device.

With the semiconductor light emitting device configured as above, thesame effect as described in the first embodiment can be obtained. Inaddition, since lead terminal 7 is projecting from resin portion 2,cutting by a die, in addition to conventional dicing, is possible.

In the first to third embodiments where the lead terminal is surroundedby resin portion 2, metal is exposed at the cutting surface the leadterminal. Oxidation of the metal reduces wettability to solder. In thesemiconductor light emitting device of the fourth embodiment, as leadterminal 7 projects toward outside (that is, into a side away from LEDchip 4), margin for solder can be ensured not only at the cuttingsurface of lead terminal 7 but at the side surface thereof, andtherefore reduction in wettability to solder can be prevented.Accordingly, when mounting the semiconductor light emitting device to asubstrate or the like, excellent soldering to lead terminal 7 can beperformed.

The other configuration of the semiconductor light emitting device ofthe fourth embodiment is the same as described in the first embodiment,and therefore detailed description thereof is not repeated.

Next, a manufacturing method of the semiconductor light emitting deviceof the fourth embodiment is described. Steps (S101)-(S106) shown in FIG.11 are similar to the steps (S1)-(S6) of the first embodiment shown inFIG. 3. In step (S101), to each of support frames (cradles) 202 of theopposing edges of lead frame base member 201, a key structure 205 isformed. Key structure 205 is provided in order to improve connectingforce between lead frame base member 201 and resin base member 207, whenresin base member 207 is formed as a gap surrounding a portion forminglead frame 1 in lead frame base member 201 is filled with resin.

In the subsequent step (S102), the gap formed so as to surround theportion forming lead frame 1 in lead frame base member 201 is filledwith resin, whereby resin base member 207 is formed. Here, in multiplelead frame 200 of the fourth embodiment shown in FIG. 12, a groovestructure 204 not being filled with resin is formed between resin basemember 207 and skeleton frame 203, which is different from the firstembodiment having a structure in which every gap is filled with resin.For example, when a gap is to be filled with resin by compressionmolding, groove structure 204 can be formed by providing a mask forpreventing intrusion of resin.

That is, as described above, in the semiconductor light emitting deviceof the fourth embodiment, resin portion 2 surrounds lead frame 1 in alimited manner with a minimum resin amount that ensures the productstrength, while the end portion of lead terminal 7 for connecting to amounting substrate or the like is not surrounded by resin portion 2.Accordingly, the portion forming lead terminal 7 in lead frame basemember 201 and skeleton frame 203 between resin base members 7 are notcovered by resin. On the other hand, between two adjacent skeletonframes 203, resin base member 207 is formed so as to reach supportframes (cradles) 202 of the opposing edge of lead frame base member 201.

Next, in step (S107), cutting by a cutting die is performed. Thematerial of the cutting die may be a material generally used for a diefor cutting a metal frame (such as cemented carbide). Since the endportion of LED terminal 7 on a side away from LED chip 4 is not coveredby resin, cutting between columns of the multiple lead frame in thedirection along skeleton frame 203 can be performed by a cutting die,instead of cutting by the dicing apparatus described in the firstembodiment.

As a result, as shown in FIG. 13, a punched portion 208 is formed in theportion where skeleton frame 203 has been formed. By punched portion208, adjacent lead frames 1 surrounded by adjacent resin base members207 are separated from each other. Since the joining force between leadframe base member 201 and resin base member 207 has been improved by keystructure 205, even after skeleton frame 203 is cut by the cutting die,resin base member 207 is connected to support frame (cradle) 202.

In this state, while each semiconductor light emitting device isconnected to support frame (cradle) 202 by resin base member 207, it iselectrically independent. Accordingly, in the subsequent step (S108), itis possible to perform a semiconductor light emitting devicecharacteristics test for each multiple lead frame. Thereafter, in step(S109), resin base member 207 is cut by the dicing apparatus, wherebythe semiconductor light emitting device is singulated. The taping stepof step (S110) is as described in the first embodiment.

According to the multiple lead frame for the semiconductor lightemitting device and the manufacturing method of the semiconductor lightemitting device of the fourth embodiment configured as described above,lead terminal 7 is cut by a die and the portion subjected to dicing isonly resin base member 207. Therefore, cutting defects such as burroccurring when metal and resin are simultaneously subjected todicing-cutting can be avoided. As groove structure 204 is formed inmultiple lead frame 200, the force required for performing die cuttingcan be reduced, while the die can be simplified and the press machinecan be reduced in size. Alternatively, a press machine of comparableperformance can produce greater pieces of semiconductor light emittingdevices. Additionally, as described above, the characteristics test thathas conventionally been performed after singulating the semiconductorlight emitting devices can be performed for each multiple lead frame.Accordingly, the production efficiency of the semiconductor lightemitting device can be improved.

Fifth Embodiment

In a fifth embodiment, another manufacturing method of a semiconductorlight emitting device shown in FIGS. 9 and 10 is described. As shown inFIG. 15, a multiple lead frame for a semiconductor light emitting deviceis different from the fourth embodiment in that resin base member 207exists only around the portion forming each lead frame 1, while eachresin base member 207 is separated by skeleton frames 203 and 206. Theadjacent semiconductor light emitting devices are not connected by resinbase member 207.

That is, each resin base member 207 is divided for each insulatorsurrounding each lead frame 1 by skeleton frames 203 and 206. Resin basemember 207 is limitedly present only around the portion forming eachlead frame 1, and it is not connected to adjacent resin base member 207forming adjacent lead frame 1.

With the multiple lead frame for the semiconductor light emitting devicestructured as above, it is only necessary to cut the end portion of leadterminal 7 in step (S207) shown in FIG. 14, and it is not necessary todice resin portion 2. That is, comparing the flowchart of FIG. 14 withFIG. 11, it is different in that each semiconductor light emittingdevice is singulated in die cutting in step (S207), and that dicing step(S109) in FIG. 11 is omitted. Accordingly, since the process isshortened, the production efficiency of the semiconductor light emittingdevice can further be improved.

The other configuration and manufacturing steps of the semiconductorlight emitting device of the fifth embodiment is the same as describedin the first and fourth embodiments, and therefore description thereofis not repeated.

Sixth Embodiment

As shown in FIG. 16, a semiconductor light emitting device of a sixthembodiment is different from the semiconductor light emitting device ofthe fourth embodiment shown in FIG. 9 in that it further includes areflector 10 provided on a side away from LED chip 4 relative to theperiphery of resin portion 2 and lead terminal 7.

Reflector 10 may be formed by white resin having a high reflectivity, toefficiently reflect the light generated by LED chip 4 and transmittedthermosetting resin 3. Also, similarly to resin portion 2, it may beformed by resin excellent in heat resistance, taking into account of areflow step in manufacturing. In order to more efficiently reflect thelight, the inner circumferential surface of reflector 10, that is thesurface opposing to LED chip 4, may be plated with silver plating,nickel plating, or nickel-chromium plating, for example. Reflector 10may be made of metal having high heat conductivity such as Al, Cu, Fe,or Mg. Reflector 10 may be connected, by an adhesive 11 made oftransparent resin such as epoxy-based resin, to substrate 12 having thepackage formed by lead frame 1 and resin portion 2 mounted thereon, orit may be bonded to substrate 12 by an adhesive sheet. The innercircumferential surface of reflector 10 may be shaped to be part ofcircular conical surface, elliptic conical surface, sphere, orparaboloid, so that light is efficiently emitted.

With the semiconductor light emitting device configured as above, thesame effect as described in the fourth embodiment can be obtained. Inaddition, the optical characteristics that cannot be realized solely bythe sealing shape of the sealing resin can be obtained, and at the sametime, light extraction efficiency is also improved. As thermosettingresin 3 is molded by die molding or dam-sheet molding, reflector 10 andthermosetting resin 3 do not contact each other as in the conventionalexample shown in FIG. 21. That is, the conventional problem of peelingdefect between reflector 10 and thermosetting resin 3 does not occur.

Reflector 10 is provided to the outer circumferential portion of thesemiconductor light emitting device. Accordingly, a package ofcollective reflector 10 as shown in FIG. 17 may be produced (the packageis a plate-like base member provided with a plurality of through holes,the inner wall of the through hole being formed in the same shape as theinner circumferential surface of reflector 10). Then, only LED packages100 already subjected to the characteristics test are mounted onmounting substrate 12. Thereafter, as shown in FIG. 18, the package ofreflector 10 can be provided to the outer circumference of LED packages100.

The other configuration and manufacturing steps of the semiconductorlight emitting device of the sixth embodiment are the same as describedin the first and fourth embodiments, and therefore description thereofis not repeated.

Seventh Embodiment

As shown in FIG. 19, a semiconductor light emitting device of a seventhembodiment is different from the semiconductor light emitting device ofthe sixth embodiment shown in FIG. 16 in that reflector 10 is providedon main surface 1 a while avoiding contact with thermosetting resin 3 asa sealing resin.

Reflector 10 may be fixed on main surface 1 a of lead frame 1 byadhesive 11, or may be fixed by an adhesive sheet. When adhesive 11 isemployed, desirably adhesive 11 is sufficiently thin in a range wherethe adhesion strength is ensured. If adhesive 11 is thick, light leaksform adhesive 11 that is transparent resin, and the light extractionefficiency is reduced.

In the semiconductor light emitting device of the seventh embodiment,the shape employed for the multiple lead frame is as shown in FIG. 12.The manufacturing method of the semiconductor light emitting device ofthe seventh embodiment shown in FIG. 20 is different from the flowchartof FIG. 11 in that, after die cutting is performed in step S307, in step(S308), the package of reflector 10 shown in FIG. 17 is bonded on mainsurface 1 a of lead frame 1 by adhesive 11, and thereafter, in step(S309), resin base member 207 and reflector 10 are cut by dicing.

With the semiconductor light emitting device configured as above, thesame effect as described in the fourth embodiment can be obtained. Inaddition, the optical characteristics that cannot be realized solely bythe sealing shape of the sealing resin can be obtained. At the sametime, since the distance between the inner circumferential surface ofreflector 10 and LED chip 4 is shortened, the light can more efficientlybe emitted to the outside, and hence light extraction efficiency is alsoimproved. Furthermore, by bonding reflector 10 on main surface 1 a, theouter shape of the semiconductor light emitting device can be maintainednot only by resin portion 2 but also by reflector 10. This improves theproduct strength of the semiconductor light emitting device. Thus, byreducing the thickness of lead frame 1 and narrowing the distance ofslit-like groove 1 m, it becomes possible to attain multi-chipconfiguration (i.e., mounting a plurality of semiconductor lightemitting devices on a mounting substrate) while keeping the size of thesemiconductor light emitting devices small.

The other configuration and the manufacturing steps of the semiconductorlight emitting device of the seventh embodiment are the same asdescribed in the first and fourth embodiments, and therefore descriptionthereof is not repeated.

Although the present embodiment has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the scopeof the present invention being interpreted by the terms of the appendedclaims.

What is claimed is:
 1. A light emitting device, comprising: an LED chip;a first lead including a top surface having a concave surface on whichsaid LED chip is mounted, and a bottom surface exposed to an external; asecond lead including a top surface, and a bottom surface exposed to theexternal; a metal wire electrically connecting said LED chip and the topsurface of said second lead; a resin dome for covering said LED chip andsaid metal wire, the end of said resin dome being located outside theconcave surface; and an insulator provided so as to surround said firstand second leads and provided between said first and second leads. 2.The light emitting device of claim 1, wherein said LED chip is locatedaway from the center of said resin dome.
 3. The light emitting device ofclaim 2, wherein a top surface of said LED chip is higher than the topsurface of said second lead at a portion outside the end of said resindome.
 4. The light emitting device of claim 3, wherein a top surface ofsaid insulator is not higher than the top surface of said first lead. 5.The light emitting device of claim 4, wherein said LED chip is mountedon the concave surface with a silver paste interposed therebetween. 6.The light emitting device of claim 4, wherein said metal wire is made ofgold.
 7. The light emitting device of claim 6, wherein said resin domeis made of silicone resin.
 8. The light emitting device of claim 4,wherein said first and second leads include copper and iron.
 9. Thelight emitting device of claim 3, wherein a top surface of saidinsulator is at substantially the same level as the top surface of saidfirst lead.
 10. The light emitting device of claim 9, wherein said LEDchip is mounted on the concave surface with a silver paste interposedtherebetween.
 11. The light emitting device of claim 9, wherein saidmetal wire is made of gold.
 12. The light emitting device of claim 11,wherein said resin dome is made of silicone resin.
 13. The lightemitting device of claim 9, wherein said first and second leads includecopper and iron.